1. Field of the Invention
The invention relates to a nontoxic polysiloxane material (PSN material), optionally a ripened polysiloxane material (rPSN material) which is preferably formed as one of several different polysiloxane materials (PSN materials). According to the invention, such an rPSN (r stands for ripe, ripened) can, for example, be spun into bioabsorbable and/or bioactive fibres as one of the PSN materials and then be further processed into fibrous nonwoven webs as other PSN materials. The present invention further relates to processes for producing the optionally ripened PSN material, the bioabsorbable and/or bioactive PSN materials and use for these materials.
2. Description of Related Art
There are many different endeavours under way to develop bioabsorbable materials for various applications in human medicine and medical engineering, but also in other technical fields such as filter technology, biotechnology or the insulant industry. Moreover, in these sectors, continually increasing requirements are imposed, especially on the bioactivity and the toxicological properties of the materials.
Absorbable Si polymers are known in the prior art. DE 196 09 551 C1 describes biodegradable and bioabsorbable fibre structures. These fibres can be obtained in a sol-gel process by drawing fibres from a spinning dope and drying them, if desired. The spinning dope contains one or more partially or completely hydrolytically condensed compounds of silicon, which are derived from monomers of the general formula SiX4 by hydrolytic condensation. The fibres have the disadvantage that degraded as-spun they do not show good results in cytotoxicity tests and in some instances even have to be categorized as cytotoxic. Such toxicity is totally undesired especially for use in human medicine, medical engineering, filter technology, biotechnology or insulant industry, especially in the field of wound healing or the filtration of cells from bodily fluids.
Moreover, the process for producing the fibres according to DE 196 09 551 C1 has the disadvantage that the resulting mixture following removal of the solvent comprises a solid and therefore has to be subjected to a filtration. Other liquid Si polymers, which may be toxic, cannot be removed at all by filtration. Furthermore, a large proportion of the spinnable sol is lost, inter alia due to the formation of the solid phase and due to the mandatory filtration step. The process in DE 196 09 551 C1 also permits the formation of a not inconsiderable proportion of a gel-like phase of highly condensed Si compounds during ripening. This again reduces the proportion of spinnable sol dope.